Effect of heat treatment on microstructure and mechanical properties of the hot-isostatic-pressed Inconel 718 powder compact
Effect of heat treatment on microstructure and mechanical properties of the hot-isostatic-pressed Inconel 718 powder compact
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DOI：
10.1016/j.jallcom.2013.12.107
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发表时间：
2014-03
影响因子：
6.2
通讯作者：
Litao Chang;Wen-ru Sun;Y. Cui;Faqiang Zhang;Rui Yang
中科院分区：
文献类型：
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作者：
Litao Chang;Wen-ru Sun;Y. Cui;Faqiang Zhang;Rui Yang
对热等静压Inconel718粉末压坯的力学性能进行了优化。根据Inconel718合金的相关系，设计了固溶+不同固溶温度时效和直接时效两种热处理方案，并对其进行了优化。结果表明，直接时效热处理是最好的时效处理方法，因为它保证了粉末压坯的强度和塑性的良好平衡。直接时效合金的拉伸和持久性能均达到Inconel718的要求。固溶处理会导致晶界强度降低和塑性变差，这是由于碳化物和δ相在先前的晶界析出或在三重结处形成热致疏松而导致的，不利于粉末压制。由于γ‘’相的过时效，直接时效合金的屈服强度略低于固溶处理合金。
The present study deals with the optimization of the mechanical properties of the hot-isostatic-pressed Inconel 718 powder compact. Several heat treatments, including the solution plus aging with different solution temperature and the direct aging scheme, have been designed based on the phase relations of Inconel 718 and been employed for the optimization. The results indicate that the direct aging heat treatment is the best one, because it ensures a good balance of the strength and ductility of the powder compact. The tensile and stress rupture properties of the direct aged alloy have all met the specifications for Inconel 718. Solution process leads to a decrease of grain boundary strength and poor ductility because of the precipitation of carbide and δ phase at the prior particle boundaries or formation of thermal induced porosities at the triple junctions, and is then not appropriate for the powder compact. Yield strength of the direct aged alloy is a little lower than the solution treated alloy because of over aging of the γ′′ precipitates.